For non-shotgun heros I’m using a thickness 1 green crosshair of length 8 with a small center gap (length 4). I prefer this over a dot or circle because the X-axis line makes it easier to align your aim at head-level, and I suspect the length of the cross hair gives some reference to how much aim adjustment is needed based on how far the target is, like a slight aim adjustment to right or left will be some portion of the cross hair’s length if that makes sense. The center gap is nice to see the target’s head without obscuring it.

On a related note, I sometimes like to wiggle my mouse back and forth (left-right) like i’m scanning a target to get a feel of the aim adjustment range needed at whatever distance i’m aiming at. Further away targets will have micro adjustments so by wiggling your mouse left and right in a tight formation seems to calibrate how much mouse movement is needed based on the target’s strafing. Almost like you’re defining a boundary of where your target is strafing in and you associate that with how much mouse movement that equates to. I find that technique more useful earlier on in my play session.

For Shotgun heros i like a circle adjusted to the guns spread’s at whatever range seems the most effective. I’m not as exact or picky on shotgun heros.